He's studied these ‘living fossils’ for over 50 years. They’re still a bit of a mystery

You know when you find someone so knowledgeable about a fascinating subject and so excited to talk about it, that you could listen to them for hours? Well, that pretty well describes paleontologist and University of Washington biology professor Peter Ward. He's an expert on one of the least understood and oldest animals on Earth.

The nautilus is a cephalopod, a type of mollusk, and a distant cousin to squids, octopi, and cuttlefish. About 500 million years ago, before the time of dinosaurs, their ancestors were among the largest, most complex, most common animals on Earth. Ward calls them “living fossils.”

Scientists know relatively little about the nautilus compared to other animals, but they've identified three new species in recent months. We asked Peter Ward to share some of his excitement about them and his responses took us to some unexpected places.

Peter Ward: Oh, there's so much we don't know. But this is really true of almost any species that lives at the depths that nautiluses do. Once you get down below about 200 to 300 feet the biology changes. The creatures down there are extremely long-lived, predation is low, but fecundity, the ability of them to reproduce, is also very low. And this is certainly the case for nautiluses. There are only two places on the planet where a diver could see them. One is New Caledonia and the other is Vanuatu. I've had the privilege to be absolutely scared out of my mind, to dive at night and find wild animals swimming up the reefs. Everywhere else, they're way, way deeper.

The word "nautilus" comes from the ancient Greek word for sailor, but as Ward suggests, they're really more of a submariner. Unlike its cousins, the nautilus lives inside a hard external shell that has multiple closed interior chambers. And a nautilus has around 90 tentacles, the most of any cephalopod.

Think about those Chinese balloons from a couple of weeks ago. Chinese balloons and nautiluses are kind of the same thing. They float along. They use very little energy. Nautiluses bounce around the bottom. They don't need much food. They expend very, very little energy. And their big shell may serve as a kind of scuba tank. They’re really able to go to places that fish can’t.

The creatures had an impressive track record of surviving extinctions until humans became interested in collecting their shells. In 2010, the United States Fish and Wildlife Service contracted Ward to track nautilus numbers.

Nobody knew how many there are down there. We had the impression there were many of them because you put a crab trap down at 1,000 feet, come back the next day, and you have some number of nautilus almost inevitably in there. These things have great sensory smell systems. They can detect carrion in water from literally miles away. They're virtually blind. They do everything by sense of smell. They're like the bloodhounds of the sea.

Due in part to Ward’s research, nautiluses became protected in 2016. Then about this time last year, Ward made a surprising discovery.

I finally said, "I'm so tired of Covid." So, I packed up the gear and headed out myself, and was able to see this explosion of numbers down there.

It was a mixed blessing. The treaty protections were working but overfishing of their predators was making for a nautilus boom. In a 2008 TED Talk on climate change, Peter Ward called the chambered nautilus his favorite animal on the planet. We asked him if he still feels that way.

I actually like humans most of all. Second place, I think, are spaniel dogs. I'm an optimist. What people are doing in conservation, what humans are able to do to recognize how to slow global change that's going to be deleterious, that makes humans my favorite. On the other hand, there are a lot of humans that I’m less happy about, more money going to weapons that could be going to climate change mitigation.

Ward shared specific concerns about humanity's future.

I think the runaway greenhouse is going to continue. Rising sea level is the greatest threat because it very quickly causes fertile land to become salinated. Most rice is grown at very, very low elevations. You just raise the sea level by two meters and a huge percentage of current rice crops are going to disappear. People get hungry, they get cranky, and they get warlike. This is my greatest fear.

Humans, we can build what we need to survive. We as a species are not going to be killed by climate change. One-hundred years from now, 200 years from now, if there are still nuclear weapons, which there probably will be, then we could see the extinction of humans, but the climate itself won't kill us. So I guess that's optimism and pessimism in the same point.

Listen to the interview by clicking the play button above.

Documentary featuring Peter Ward's nautilus research